Shareholders' Equity - Changes in Balances of Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,879,141	$ 1,571,193	$ 1,661,847	$ 1,492,268
Other comprehensive income (loss) before reclassification			42,444	(21,394)
Amounts reclassified from accumulated other comprehensive income (loss)			148,234	8,909
Other comprehensive income (loss), net of tax amount	62,512	(22,184)	190,678	(12,485)
Balance	1,980,096	1,570,351	1,980,096	1,570,351
Securities Available for Sale and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(204,670)	(254,442)
Other comprehensive income (loss) before reclassification			43,949	(2,967)
Amounts reclassified from accumulated other comprehensive income (loss)			137,094	0
Other comprehensive income (loss), net of tax amount			181,043	(2,967)
Balance	(23,627)	(257,409)	(23,627)	(257,409)
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(6,075)	(5,792)
Other comprehensive income (loss) before reclassification			0	0
Amounts reclassified from accumulated other comprehensive income (loss)			250	243
Other comprehensive income (loss), net of tax amount			250	243
Balance	(5,825)	(5,549)	(5,825)	(5,549)
Cash Flow Hedge Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(8,978)	(15,169)
Other comprehensive income (loss) before reclassification			(1,505)	(18,427)
Amounts reclassified from accumulated other comprehensive income (loss)			10,890	8,666
Other comprehensive income (loss), net of tax amount			9,385	(9,761)
Balance	407	(24,930)	407	(24,930)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(91,557)	(265,704)	(219,723)	(275,403)
Balance	$ (29,045)	$ (287,888)	$ (29,045)	$ (287,888)